In measurement of non-faradaic admittance (or tensammetry), a plot of
alternating current against
applied potential shows a minimum or maximum when a non-
electroactive substance undergoes
adsorption or
desorption at the surface of the
indicator electrode.
Such a maximum or minimum may be called an apex to emphasize its non-faradaic origin
and distinguish it from a '
summit', which would result from a charge-transfer process. The highest value of the current
on such an apex may be called an apex current, and the corresponding
applied potential may be called an apex potential.
Source:
PAC, 1985, 57, 1491
(Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations
1985))
on page 1494